Cathode ray tube clamping centering device



Oct; 27, 1959 A. H. VALENTINE AL 2,910,604

CATHODE RAY TUBE CLAMPING CENTERING DEVICE Filed June 6, 1957 IIIIIIIIJ I la INVENTOR. 19L SE57 1?! VHL EN Tl/VE HTTOEN 7? V w United tates Patent CATHODE RAY TUBE CLAMPING CENTERING DEVICE Albert H. Valentine, Baltimore, and Thomas M. Moore,

. Glen Burnie, Md., assignors, by mesne assignments, to

the United States of America as represented by the Secretary of the Air Force Application June 6, 1957, fierlal No. 664,146

2 Claims. (Cl. 313-84) This invention relates generally to a means for centering an electron beam on the face of a cathode ray tube and, more particularly, to a device that acts simultaneously as a tube clamp and an electron beam centering means.

In the use of cathode ray tubes for television receivers and radar, it is essential that the electron beam emitted therefrom be centered relative to the tube axis and thereby be centered on the fluorescent screen or end wall to avoid distortion. Moreover, it is highly important that some means be utilized for clamping the tube securely in place in order to avoid shock or vibration damage.

It is an object of the invention, therefore, to provide an improved device which centers the electron beam emitted from a cathode ray tube on the end wall or fluorescent screen thereof.

A further object of the invention involves a simple and improved mechanism that acts both as a tube clamp and beam centering means.

A still further object of the invention utilizes an adjustable magnetically controlled means having positive means for locking said magnetically controlled means in a selected position.

Another object of the invention involves the use of a pair of ring magnets adjustable between predetermined limits to control the direction of an. electron beam in transverse directions andthereby assure accurate centering thereof.

An additional object of the invention provides a cathode ray tube electron beam centering device adaptable for use with either magnetically controlled or electrostatically controlled cathode ray tubes.

Other objects and advantages of the invention will become apparent from the following description, taken in connection with the accompanying drawings, in which like reference characters refer to like parts in the several figures.

Fig. 1 is a front view of the beam centering and cathode ray tube clamp utilized in the invention, illustrating the relation between the mounting frame and the magnetic rings.

Fig. 2 is an exploded view taken about on section 22 of Fig. 1, illustrating details of the inventive device in their disassembled condition.

With particular reference to Fig. 2 of the drawings, the beam centering and clamp device of the invention is indicated generally at 1 and includes a mounting bracket or frame 2, a threaded and knurled clamp ring 3, a metal washer 4, a sponge rubber Washer 5, two knurled phenolic rings 6, and two permanent ring-shaped magnets 7 to be referred to hereinafter as ring magnets. Each phenolic ring 6 incorporates a circular groove 8 (shown in dotted lines in Fig. 1) into each of which grooves 8 one of said permanent ring magnets 7 is securely fastened. A mounting frame leg 9 is incorporated at each corner of, and extends at right angles to the plane of said mounting frame or bracket 2. Said mounting frame or bracket 2, also, incorporates a countersunk portion 2a interiorly of ice legs 9, and an interiorly threaded portion 2b remote from legs 9. In order to properly assemble said beam centering and clamp device 1, metal washer 4 and sponge rubber washer 5 are inserted in concentric relation in said countersunk portion 2a, phenolic rings 6 are then placed between mounting frame legs 9 in concentric relation, and the entire assembly is bolted to the gear box or yoke mounting plate indicated partially broken away at 10 by means of a projection 9a atfixed on the end of each leg 9 being engaged in the drilled and internally threaded openings or recesses 10a incorporated in said gear box or yoke mounting plate 10. It is noted that the entire assembly has a central opening indicated at 11 into which opening 11 the neck of a cathode ray tube (not shown) is adapted to be assembled. At this point, the clearance between washers 4 and 5 and rings 6 is sufficient to permit free rotation of the latter relative to one another to a selected position required for proper electron beam centering. After adjusting said rings 6 to their desired relative position in order to either cancel or add their magnetic fields in order to attain the desired centering, clamp ring 3 is screwed into mounting frame 2 and locked in place to compress the sponge rubber in washer 5 between metal washer 4- and the rings 6 and the face of the gear box or yoke mounting plate 19 and thus positively retain the neck of the cathode ray tube mounted therein and simultaneously hold rings 6 in their adjusted position.

Referring specifically to Fig; 1 of the drawings, the relationship between the four frame legs 9 and rings 6 is clearly seen. Each leg 9 incorporates an arcuate portion 9b adjacent to but out of contact with the knurled surface of rings 6. Thus, in order to adjust or re-adjust the relative position between phenolic rings 6, it is only necessary to unscrew clamp ring 3, grasp the knurled circumference of either, or both, of said phenolic rings 6 to rotate the latter to a new position, and then retighten or screw said clamp ring 3. In this manner, precise adjustment required for proper beam centering is facilitated, even though the device of the present invention is in its tube mounted condition.

Thus, a unique and yet simple arrangement has been efiected by the device of the instant invention wherein an inexpensive means has been developed for centering an electron beam on the face of a cathode ray tube by the utilization of a pair of permanent magnets concentrically adjustable relative to each other to a desired position and in which the means provided for positively retaining said magnets in their adjusted position, also, acts as a positive clamp on the neck portion of the cathode ray tube mounted therein in order to avoid damage thereto due to vibration or shock.

We claim:

1. A beam centering and tube clamping device comprising a mounting frame having a central opening extending therethrough and a plurality of oppositely disposed cutout surfaces disposcd on the circumference thereof, a countersunk portion surrounding said opening on one side of said frame, an interiorly threaded portion surrounding said opening on the side of said frame remote from said countersunk portion and a plurality of mounting leg supports circumferentially disposed in affixed relation on each corner of said frame in surrounding relation to said opening, a metal washer mounted in said countersunk portion and having a central opening in alignment with the central opening of said frame to receive the neck portion of a tube in clamping relation therein, a sponge rubber washer concentrically mounted in said countersunk portion in contact with and outwardly of said metal washer and having a similar aligned central opening adapted to receive the neck portion of a tube in clamping relation therein, a pair of rings of insulating "9 material concentrically mounted in clamping relation on the neck portion of the tube adjacent said washers between said mounting supports and having a knurled circumferential surface partly disposed in overlapping relation to the cutout surfaces of said mounting frame and central openings in alignment with said'first-named central opening, a ring-shaped permanent magnet affixed to each of said pair of rings, a gear box affixed to said mounting supports outwardly of said pair of rings, and an exteriorly threaded clamp ring in threaded engagement with said mounting frame remote from said gear box for engaging said metal washer for applying pressure between said washers and said rings to provide clamping pressure on the neck portion of the tube.

2. A cathode ray tube electron beam centering and tube clamping means comprising a main support bracket having a plurality of mounting support legs adapted for attachment to a mounting plate, a central recessed portion at one side thereof inwardly of said support legs, a threaded central opening in said main support bracket communicating between said recessed portion and the other side of said support bracket and adapted to receive the neck portion of a cathode ray tube, said plurality of mounting support legs peripherally disposed on said support bracket and extending in parallel circumferential relation to the longitudinal axis of the central opening, a pair of insulator rings each incorporating a central opening in alignment with the central opening of said main support bracket adapted to receive the neck portion of the cathode ray tube and each having a ring-shaped groove and adjustable relative to each other and a knurled surface periphery disposed interiorly of, and adjacent to, and in spaced relation with said plurality of mounting support legs, resilient spacer means positioned between said pair of rings and said recessed portion incorporating a portion having a central opening in alignment with the central opening of said support bracket and adapted to receive the neck portion of the cathode ray tube, said mounting plate constituting a first locking means retaining said pair of rings and said resilient spacer means in relatively loose relation on the neck portion of the cathode ray tube within said main support bracket, a ring-shaped permanent magnet afiixed in each of said ring grooves, and second locking means in locking engagement with the threaded central opening of said main support bracket on the side thereof opposite from said mounting plate in contact with said resilient spacer means to positively lock said resilient spacer means in compressed relation to said pair of insulator rings and on the neck portion of the cathode ray tube in the fully assembled position of adjustment.

References Cited in the file of this patent UNITED STATES PATENTS 2,525,919 Loughren Oct. 17, 1950 2,646,522 Shaw et a1. July 21, 1953 2,653,262 Bowman Sept. '22, 1953 2,795,717 Finkelstein et al June 11, 1957 

